Measuring absolute irradiance with AS7265X

Sensors Imaging
1

I am embedding AS7265X sensor on the side of glass frame as personal measurement device to measure absolute irradiance (microW/cm2). I also use another spectrometer (Avantes) as well for the same purpose. The problem is, the absolute irradiance i get from AS7265X is different with what i get from Avantes!!!

So i have two questions:

  1. I get confused how to find out AS7265X is accurate enough to use in my study in comparison with hight resolution spectrometer?

  2. If i want to use another spectrometer how to compare absolute irradiance (w/m2) ? As each report different number!

I would appreciate your help.

Best regards,

Armin

2

Hi Armin,

I am afraid we are not going to be able to assist you with these questions as this is beyond the scope of our support. This is a much less sophisticated spectroscopy sensor than a lab-grade spectrometer like the Avantes tool you are using and we are not able to help compare the two. That would require taking measurements from both devices as well as adjusting the settings and possibly LEDs on the SparkFun Triad Spectroscopy Sensor breakout to determine any discrepancies in data between the two.

I would recommend reviewing the various resources we have available such as the [AS7265X Datasheet, the [Hookup Guide and the [Arduino Library. We also have datasheets available for the three LEDs on the board ([white, [IR and [UV) for you to review and, if needed, you can replace them by modifying the board. The Hardware Overview section of the Hookup Guide linked above goes into that process in more detail.](https://cdn.sparkfun.com/assets/c/4/e/1/7/UV_LED_vlmu3100.pdf)](https://cdn.sparkfun.com/assets/f/a/1/b/5/IR_LED.pdf)](https://cdn.sparkfun.com/assets/9/e/3/f/e/White_LED_DS208.pdf)](SparkFun_AS7265x_Arduino_Library/examples at main · sparkfun/SparkFun_AS7265x_Arduino_Library · GitHub)](https://learn.sparkfun.com/tutorials/spectral-triad-as7265x-hookup-guide)](https://cdn.sparkfun.com/assets/c/2/9/0/a/AS7265x_Datasheet.pdf)

3

Thanks for your response. I have a question regarding the output from the spectrometer sensor (AS7265X) which is reported on count. Since I need output in the unit of micro w/cm2, based on the data sheet I have difficulty on how converting the reported data to micro w/cm2.

My understanding is that this is a calibrated device (pages 13 to 18 of the document) and for all types of light including incandescent, LED, etc. the response of the device is equal to 1 micro Watt/cm^2 for one count. Please let me know If I am wrong.

Thanks,

Armin

4

TS-Mark:
Hi Armin,

I am afraid we are not going to be able to assist you with these questions as this is beyond the scope of our support. This is a much less sophisticated spectroscopy sensor than a lab-grade spectrometer like the Avantes tool you are using and we are not able to help compare the two. That would require taking measurements from both devices as well as adjusting the settings and possibly LEDs on the SparkFun Triad Spectroscopy Sensor breakout to determine any discrepancies in data between the two.

I would recommend reviewing the various resources we have available such as the [AS7265X Datasheet, the [Hookup Guide and the [Arduino Library. We also have datasheets available for the three LEDs on the board ([white, [IR and [UV) for you to review and, if needed, you can replace them by modifying the board. The Hardware Overview section of the Hookup Guide linked above goes into that process in more detail.
[/quote]

Thanks for your response. I have a question regarding the output from the spectrometer sensor (AS7265X) which is reported on count. Since I need output in the unit of micro w/cm2, based on the data sheet I have difficulty on how converting the reported data to micro w/cm2.

My understanding is that this is a calibrated device (pages 13 to 18 of the document) and for all types of light including incandescent, LED, etc. the response of the device is equal to 1 micro Watt/cm^2 for one count. Please let me know If I am wrong.

Thanks,

Armin](https://cdn.sparkfun.com/assets/c/4/e/1/7/UV_LED_vlmu3100.pdf)](https://cdn.sparkfun.com/assets/f/a/1/b/5/IR_LED.pdf)](https://cdn.sparkfun.com/assets/9/e/3/f/e/White_LED_DS208.pdf)](SparkFun_AS7265x_Arduino_Library/examples at main · sparkfun/SparkFun_AS7265x_Arduino_Library · GitHub)](https://learn.sparkfun.com/tutorials/spectral-triad-as7265x-hookup-guide)](https://cdn.sparkfun.com/assets/c/2/9/0/a/AS7265x_Datasheet.pdf)

5

As far as I understand it, that is correct. The [Arduino Library is just calling the registers for the various channels on the AS7265X depending on whether or not you want the RAW or Calibrated data from the sensor.](GitHub - sparkfun/SparkFun_AS7265x_Arduino_Library: An Arduino library for the trifecta of spectral sensors covering 18 discrete wavelengths from NIR to UV.)